Buggy code:
public class DefaultSockJsService extends AbstractSockJsService { private static final boolean jackson2Present = ClassUtils . isPresent ( "com.fasterxml.jackson.databind.ObjectMapper" , DefaultSockJsService . class . getClassLoader ( ) ) ; private static final boolean jacksonPresent = ClassUtils . isPresent ( "org.codehaus.jackson.map.ObjectMapper" , DefaultSockJsService . class . getClassLoader ( ) ) ; private final Map < TransportType , TransportHandler > transportHandlers = new HashMap < TransportType , TransportHandler > ( ) ; private SockJsMessageCodec messageCodec ; private final List < HandshakeInterceptor > interceptors = new ArrayList < HandshakeInterceptor > ( ) ; private final Map < String , AbstractSockJsSession > sessions = new ConcurrentHashMap < String , AbstractSockJsSession > ( ) ; private ScheduledFuture sessionCleanupTask ; public DefaultSockJsService ( TaskScheduler taskScheduler ) { } public DefaultSockJsService ( TaskScheduler taskScheduler , Collection < TransportHandler > transportHandlers , TransportHandler ... transportHandlerOverrides ) { } private void initMessageCodec ( ) { } protected final Set < TransportHandler > getDefaultTransportHandlers ( ) { Set < TransportHandler > result = new HashSet < TransportHandler > ( ) ; result . add ( new XhrPollingTransportHandler ( ) ) ; result . add ( new XhrReceivingTransportHandler ( ) ) ; result . add ( new JsonpPollingTransportHandler ( ) ) ; result . add ( new JsonpReceivingTransportHandler ( ) ) ; result . add ( new XhrStreamingTransportHandler ( ) ) ; result . add ( new EventSourceTransportHandler ( ) ) ; result . add ( new HtmlFileTransportHandler ( ) ) ; try { result . add ( new WebSocketTransportHandler ( new DefaultHandshakeHandler ( ) ) ) ; } catch ( Exception ex ) { if ( logger . isWarnEnabled ( ) ) { <START_BUG> logger . warn ( ( "Failed<seq2seq4repair_space>to<seq2seq4repair_space>add<seq2seq4repair_space>default<seq2seq4repair_space>WebSocketTransportHandler:<seq2seq4repair_space>" + ( ex . getMessage ( ) ) ) ) ; <END_BUG> } } return result ; } protected void addTransportHandlers ( Collection < TransportHandler > handlers ) { } public void setHandshakeInterceptors ( List < HandshakeInterceptor > interceptors ) { } public List < HandshakeInterceptor > getHandshakeInterceptors ( ) { } public void setMessageCodec ( SockJsMessageCodec messageCodec ) { } public SockJsMessageCodec getMessageCodec ( ) { } public Map < TransportType , TransportHandler > getTransportHandlers ( ) { } @ Override protected void handleRawWebSocketRequest ( ServerHttpRequest request , ServerHttpResponse response , WebSocketHandler wsHandler ) throws IOException { } @ Override protected void handleTransportRequest ( ServerHttpRequest request , ServerHttpResponse response , WebSocketHandler wsHandler , String sessionId , String transport ) throws SockJsException { } private WebSocketSession createSockJsSession ( String sessionId , SockJsSessionFactory sessionFactory , WebSocketHandler wsHandler , Map < String , Object > handshakeAttributes , ServerHttpRequest request , ServerHttpResponse response ) { } @ Override protected boolean isValidTransportType ( String lastSegment ) { } private void scheduleSessionTask ( ) { } private String getJsessionIdCookieValue ( HttpHeaders headers ) { } private final SockJsServiceConfig sockJsServiceConfig = new SockJsServiceConfig ( ) { @ Override public int getStreamBytesLimit ( ) { } @ Override public long getHeartbeatTime ( ) { } @ Override public TaskScheduler getTaskScheduler ( ) { } @ Override public SockJsMessageCodec getMessageCodec ( ) { } @ Override public int getHttpMessageCacheSize ( ) { } } ; }

Fix:
logger . warn ( "Failed<seq2seq4repair_space>to<seq2seq4repair_space>create<seq2seq4repair_space>default<seq2seq4repair_space>WebSocketTransportHandler" , ex ) ;